The main objective of this proposal is to utilize genetic engineering methodologies to develop a safe and effective subunit vaccine for preventing infection by the AIDS (Acquired immune deficiency syndrome) retrovirus. AIDS and ARC (AIDS-related complex) are significant causes of morbidity and mortality in the U.S. and on the African continent. Currently, there is no effective treatment for limiting disease or inhibiting the AIDS retrovirus. This proposal will investgate immunological properties of viral antigens expressed in genetically engineered yeast and mammalian cells; similar expression vectors are being utilized for the production of other vaccines (e.g., Hepatitis B Virus) and for production of enzymes and hormones for therapeutic use in humans. The research effort on the AIDS system in this proposal will contribute to our understanding both basic aspects of pathogenesis and fundamental mechanisms of immunity.